Composite materials composed of fiber reinforced plastic (FRP) and plywood or aluminum are widely used in automotive applications, such as for truck body sidewall panels, because of their low cost and structural properties. However, significant problems are associated with these materials. Composite panels having one or more plywood layers are subject to water absorption, rot, and mold growth. Likewise, composite panels having metal layers are subject to corrosion. Further, automotive panels made of composites using either plywood or metal tend to be heavy, which results in less efficiency and high fuel costs for the vehicle.